The invention relates to a distributed data management mechanism and in particular, to a distributed data management mechanism wherein the data may be distributed noncontiguously in one or more storage areas.
In conventional distributed processor systems, many different processes are executing on different processors. Some processors are causing more than one process to be executed. Many times, the processes are required to pass data required for execution of work. A requestor process generates work requests which have associated data. A server of work is required to receive data related to the work request from the requesting process. This is even necessary when the server's only purpose is to modify a command to add header and trailer information to the original data, or data stream and pass the modified data stream to another server in a hierarchy of servers. If the processes are executing on the same processor, the data remains in that processor's storage and is accessible by both processes.
IBM Technical Disclosure Bulletin Vol. 23 No. 5 October 1980, Distributed Data Processing System, describes a processing system wherein system resources belong to processes and communication between processes is indirect via supervisor services. This provides some process mobility. Communication is in terms of messages processed by subsystem communication facilities. IBM Technical Disclosure Bulletin Vol. 22 No. 7 December 1979, Message-Based Protocol for Interprocessor Communication, discloses a message-based protocol for communicating between processes executing on different processors loosely coupled via a common bus. Processes are defined as execution units which interact through message queues and through shared variables.
The movement of data with the work requests results in extraneous data moves across physical transport mechanisms connecting the processors. It also places an unnecessary storage requirement on the processors where the data must be received, but is not acted on.